Gas production by intestinal microflora of lactose maldigesters

To investigate whether the gas produced by faecal contents of lactose maldi gesters is traceable to symptoms of intolerance we analysed by gas chromato graphy faecal extracts of frozen stool samples for their gas composition. T he samples were taken from 21 patients with biopsy-proven hypolactasia, 10 with severe and 11 with mild symptoms (cumulative score), and were incubate d in three different carbohydrate broths. After incubation, H-2, CO2, air a nd methane contents were analysed in triplicate. Differences between patien t groups with mild and severe symptom scores were found, but they did not r each statistical significance. Substantial intragroup variations in gas pro duction among patients with severe (range of H-2 in galactose: 0.9-8.3%, an d range of CO2: 5.9-15.9%) as well as with mild symptoms (H-2: 0-8.3%, and CO2 1.4-14.5%) were recorded. Two patients with severe and one with mild sy mptoms produced detectable amounts of methane. The individual symptoms, i.e . flatulence or abdominal pain, did not directly correlate with gas product ion, but abundant gas production had a tendency to associate with a greater difference in waistline measurements before and after lactose provocation. Preliminary comparisons between faecal H-2 and CO2 production and bacteria l groups isolated from the samples showed that high concentrations of Esche richia coli tended to be more often associated with high gas production. Nu mbers of lactobacilli and H-2 concentrations showed a trend towards negativ e correlation. (C) 1999 Academic Press.